1. Field of the Invention
This invention relates to methods for preparing alkyl diarylborinates and methods for preparing complexed diarylboronic acids, which are useful as antibacterial agents.
2. Description of the Related Art
N—O complexed diarylboronic acids are known to be effective pharmaceutical agents. For example, such compounds are capable of inhibiting adenine DNA methyltransferases in bacterial cells and thus exhibit antibacterial, growth-inhibitory properties against any bacterial species that produces an adenine DNA methyltransferase. Antibacterial diarylboronic acids are described in International Application Publication No. WO 00/75142.
Currently available methods for the preparation of N—O complexed diarylboronic acids require the use of dichloroborane methyl sulfide complex as a starting material. The use of dichloroborane methyl sulfide complex has several disadvantages, including the formation of dimethyl sulfide (DMS) as a side product of the reaction. Further, dichloroborane methyl sulfide reacts violently with water to produce flammable and harmful gases and has a repugnant odor that causes great discomfort for any lab personnel working with the material.
The formation of DMS as a side product makes the process of isolating a reaction product without contaminating the working area with DMS extremely difficult. Like dichloroborane methyl sulfide complex, DMS also has a foul odor. Further, DMS is a cancer suspect agent.
A need exists, therefore, for a method for preparing N—O complexed diarylboronic acids, and complexed diarylboronic acids in general, that is safer, more versatile and friendlier to lab personnel than currently known methods.